rewrite dispatcher system

README.rst

@@ -26,10 +26,13 @@ An example for when subscribing to the on_member_kick event.
 
     import discord
     from discord.ext import commands, events
-    from discord.ext.events import member_kick
+    from discord.ext.events import EventsMixin, CustomEventDispatcher
 
 
     class MyBot(commands.Bot, events.EventsMixin):
+        dispatcher = CustomEventDispatcher([
+            'member_kick',
+        ])
 
         async def on_ready(self):
             print('Logged in!')

discord/ext/events/__init__.py

@@ -17,6 +17,7 @@
 from collections import namedtuple
 
 from .mixins import EventsMixin
+from .dispatcher import CustomEventDispatcher
 from . import utils
 
 

discord/ext/events/custom_events/__init__.py

@@ -0,0 +1,5 @@
+from typing import Callable, Dict
+
+# Filled at run time
+_ALL: Dict[str, Callable] = {}
+

discord/ext/events/member_kick.py → discord/ext/events/custom_events/member_kick.py

@@ -1,26 +1,17 @@
 import discord
 
-from ._events import _ALL
-from .utils import fetch_recent_audit_log_entry, listens_for
-
-
-EVENT_NAME = 'member_kick'
+from ..utils import fetch_recent_audit_log_entry, listens_for
 
 
 @listens_for('member_remove')
 async def check_member_kick(client: discord.Client, member: discord.Member):
     guild = member.guild
 
-    print('!RAN')
-
     if not guild.me.guild_permissions.view_audit_log:
         return
 
     entry = await fetch_recent_audit_log_entry(client, member.guild, target=member, action=discord.AuditLogAction.kick, retry=3)
     if entry is None:
         return
 
-    client.dispatch(EVENT_NAME, member, entry)
-
-
-_ALL[EVENT_NAME] = check_member_kick
+    return member, entry

discord/ext/events/dispatcher.py

@@ -0,0 +1,27 @@
+import asyncio
+from typing import List, Optional
+
+import discord
+
+from .custom_events import _ALL
+from .errors import InvalidEvent
+
+
+class CustomEventDispatcher:
+    def __init__(self, listening_to: Optional[List[str]]=None):
+        valid_handlers = _ALL
+
+        if listening_to:
+            try:
+                valid_handlers = {name: _ALL[name] for name in listening_to}
+            except KeyError as e:
+                raise InvalidEvent('no registered handler for {!r}'.format(e.args[0]))
+
+        self.valid_handlers = valid_handlers
+
+    def handle(self, client: discord.Client, event: str, *args, **kwargs):
+        if event in self.valid_handlers:
+            return
+
+        for event_check in self.valid_handlers.values():
+            asyncio.ensure_future(event_check(client, event, *args, **kwargs))

discord/ext/events/errors.py

@@ -0,0 +1,7 @@
+from discord.errors import DiscordException
+
+class EventsException(DiscordException):
+    pass
+
+class InvalidEvent(EventsException):
+    pass

discord/ext/events/mixins.py

@@ -1,16 +1,11 @@
-import asyncio
-
 import discord
 
-from ._events import _ALL
+from .dispatcher import CustomEventDispatcher
 
 
 class EventsMixin(discord.Client):
-
-    async def on__event(self, event, *args, **kwargs):
-        for event_name, event_check in _ALL.items():
-            asyncio.ensure_future(event_check(self, event, *args, **kwargs))
+    dispatcher = CustomEventDispatcher()
 
     def dispatch(self, event, *args, **kwargs):
         super().dispatch(event, *args, **kwargs)  # type: ignore
-        super().dispatch('_event', event, *args, **kwargs)
+        self.dispatcher.handle(self, event, *args, **kwargs)

discord/ext/events/utils.py

@@ -1,11 +1,12 @@
 import asyncio
 import datetime
-
 from functools import wraps
 from typing import Callable, Optional
 
 import discord
 
+from .custom_events import _ALL
+
 
 SLEEP_FOR = 2.5
 
@@ -68,11 +69,17 @@ def listens_for(*events: str) -> Callable:
     """
 
     def decorator(func: Callable) -> Callable:
+        event_name = func.__name__[6:]
+        _ALL[event_name] = func
 
         @wraps(func)
         async def wrapper(client, event, *args, **kwargs):
             if event in events:
-                await func(client, *args, **kwargs)
+                result = await func(client, *args, **kwargs)
+                if result is not None:
+                    if not isinstance(result, tuple):
+                        result = (result,)
+                    client.dispatch(event_name, *result)
 
         return wrapper
 

setup.py

@@ -17,7 +17,7 @@
     python_requires=">=3.5.3",
     url="https://github.com/Ext-Creators/discord-ext-events",
     version=version,
-    packages=["discord.ext.events"],
+    packages=["discord.ext.events", "discord.ext.events.custom_events"],
     license="Apache Software License",
     description="Custom events derived from events dispatched by Discord. ",
     long_description=readme,